Disposable paperboard cartons have long been commercially available for storing, transporting and selling both powder and granular type materials. For decades, these cartons contained metal pour spouts which were hinged to allow easy opening of the carton for initial use and easy closing of the carton for storage.
In an effort to reduce the costs of manufacture and the complexity of carton making machinery, fabricators have sought ways to replace the metal pour spout with one made of paperboard.
A number of containers have been designed wherein the pour spout and reclosure tab are constructed of paperboard. One such design is illustrated in U.S. Pat. No. 3,226,003 to Hickin. This patent discloses a carton having a vertically extending spout located in its narrow side wall together with a reclosable tab. Reclosure is effected by pushing the lower end of the tab into a discharge opening formed in an underlying sidewall. This reclosure feature was an improvement over prior containers. However, by cutting the discharge opening from the lateral edge of the carton blank, the integrity of the carton during manufacture may be affected, and the stability to vary the size of the discharge opening for varying product size without necessitating a change in the closure flap is not possible. The closure flap pivots about a horizontal hinge line and lifting of the tab is in an upward vertical direction.
U.S. Pat. No. 3,563,447 issued to Katzenmeyer discloses a carton having a horizontal pull tab with a vertical pour spout. The tear panel pivots about a vertical fold line. However, the discharge opening is provided by limiting the length of the underlying panel making it impossible to vary the size of the spout opening without significantly altering the closure flap as well.